Cuttlefish

Originally posted on the Monterey Bay Aquarium Blog, we provide this intro to their story about an amazing improvised Cuttlefish incubation system:

How do you incubate Cuttlefish eggs behind the scenes in preparation for [Monterey Bay Aquarium's] forthcoming “Tentacles” special exhibition? You could, at a cost of hundreds of dollars, buy commercial incubators. But that would be too easy. Plus, Aquarist Bret Grasse figured he could create something just as good as the store-bought jobs.

For $2.50 and “a day in the life of one volunteer,” he makes a better bubbler out of soda bottles, plastic tubing and silicone glue. It looks like mad science, but it works. To date, he’s produced hundreds of baby cuttlefish for exhibit using the system.

Kentucky's Newport Aquarium has a bundle of new arrivals in the form of many baby Cuttlefish. What's a Cuttlefish? It belongs to the same class as squids and octopuses. Regardless of the word "fish" in their name, they are actually mollusks, living mostly in shallow waters -- though they are known to reside in deeper areas as well. They are found along the coasts of east and south Asia, western Europe, the Mediterranean, as well as all coasts of Africa and Australia.

Cuttlefish come from eggs, the cases of which progress from dark and opaque to light and nearly clear as they approach hatching stage.

For keepers, seeing the newly hatched cuttlefish eating (below) is very important, because it is the main marker that the babies are healthy and will grow. One of the small fish they eat as babies is brine shrimp.

Once fully grown, their preferred diet consists of crabs and fish. They have the ability to use camoflage to sneak up on their prey. When they get close, their eight arms open up and shoot out two long feeding tentacles. On the end of each is a sucker-covered pad that attaches to prey and pulls it toward them.

For the past few weeks aquarists at the Tennessee Aquarium have been monitoring an egg mass which was laid by a cuttlefish pair born and reared at the Aquarium. Shortly after the eggs were removed from the exhibit and placed into a holding tank, tiny cuttlefish began hatching. Carol Haley, the Aquarium’s assistant curator of fishes, said, “The first day about 42 hatchlings appeared. Another 40 or so appeared the following day.”

The hatchlings, called cuttlets, are tiny replicas of their parents. Each individual is small enough to fit inside a quarter teaspoon. Once they emerge from the egg sac, they begin hunting. “They have a pretty big appetite and are ready to use their tentacles to snare the live mysid shrimp we feed them,” said Haley.

These babies are too small to be placed on exhibit like their parents. Right now they use their chromatophores to look like tiny pebbles in the bottom of the holding tank they’ll call home for the next few months. They also use another trick to avoid being a tiny treat for a predator. “Even at their small size they can produce ink,” said Haley. “They will ink more as feisty teenagers, usually when they reach about six months of age.”

When they are six to seven months old, they’ll be large enough to go on exhibit. Until then, Aquarium guests can see these miniature cuttlefish in the Quarantine Room during the 1:30 p.m. Backstage Pass Tour. “Cuttlefish babies are super cute as babies and people are still fascinated by them when they reach adulthood,” said Haley. “They might be the most adorable ‘sea monsters’ you’ll ever see.”